Efficacy and Safety Study of Buprenorphine HCl Buccal Film in Subjects With Low Back Pain

Inclusion Criteria: * Male or non-pregnant and non-nursing female aged 18 or older * History of moderate to severe chronic low back pain for ≥3 months with a pain intensity ≥5 \[11 point numerical rating scale\] reported at the open-label titration period Day 0/1 visit following a washout period (opioids, nonsteroidal anti-inflammatory drugs \[NSAIDs\], and muscle relaxants) of approximately 12 to 24 hours * Currently taking ≤60 mg oral morphine/day or equianalgesic dose of another opioid (including opioid naïve) for 1 week or longer * Stable health, as determined by the Investigator, on the basis of medical history, physical examination, and screening laboratory results so as to comply with all study procedures * Female subjects of childbearing potential must be using a recognized effective method of birth control * Written informed consent obtained at Screening, prior to any procedure being performed Exclusion Criteria: * Reflex sympathetic dystrophy or causalgia (complex regional pain syndrome), acute spinal cord compression, cauda equina compression, acute nerve root compression, meningitis, and discitis * Surgical procedure for back pain within 2 months prior to screening or nerve/plexus block within 4 weeks of screening * Hypokalemia or clinically unstable cardiac disease, including: unstable atrial fibrillation, symptomatic bradycardia, unstable congestive heart failure, or active myocardial ischemia * Corrected QT (QTc) interval of \>450 milliseconds on the 12-lead electrocardiogram (ECG) * History of long QT syndrome, or an immediate family member with this condition * Diagnosis of moderate to severe hepatic impairment. * History of severe emesis with opioids * Clinically significant sleep apnea